Retractable pen



FIG. 1 is a front, elevational view of a retractable pen showing our new design, the back elevational view being a mirror image of the front elevation view;

FIG. 2 is a left side elevational view of thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a perspective view thereof.

The stippling shown on the grip and the top push button of the pen represents a contrast of tone and is part of the claimed design. 

The ornamental design for a retractable pen, as shown and described. 